Let's get this math done. We have 15 and we're going to multiply it by 165. This is the same as taking 15 and adding it to itself 165 times.
Step 1: 0 + 15 = 15
Step 2: 15 + 15 = 30
Step 3: 30 + 15 = 45
Step 4: 45 + 15 = 60
Step 5: 60 + 15 = 75
Step 6: 75 + 15 = 90
Step 7: 90 + 15 = 105
Step 8: 105 + 15 = 120
Step 9: 120 + 15 = 135
Step 10: 135 + 15 = 150
Step 11: 150 + 15 = 165
Step 12: 165 + 15 = 180
Step 13: 180 + 15 = 195
Step 14: 195 + 15 = 210
Step 15: 210 + 15 = 225
Step 16: 225 + 15 = 240
Step 17: 240 + 15 = 255
Step 18: 255 + 15 = 270
Step 19: 270 + 15 = 285
Step 20: 285 + 15 = 300
Step 21: 300 + 15 = 315
Step 22: 315 + 15 = 330
Step 23: 330 + 15 = 345
Step 24: 345 + 15 = 360
Step 25: 360 + 15 = 375
Step 26: 375 + 15 = 390
Step 27: 390 + 15 = 405
Step 28: 405 + 15 = 420
Step 29: 420 + 15 = 435
Step 30: 435 + 15 = 450
Step 31: 450 + 15 = 465
Step 32: 465 + 15 = 480
Step 33: 480 + 15 = 495
Step 34: 495 + 15 = 510
Step 35: 510 + 15 = 525
Step 36: 525 + 15 = 540
Step 37: 540 + 15 = 555
Step 38: 555 + 15 = 570
Step 39: 570 + 15 = 585
Step 40: 585 + 15 = 600
Step 41: 600 + 15 = 615
Step 42: 615 + 15 = 630
Step 43: 630 + 15 = 645
Step 44: 645 + 15 = 660
Step 45: 660 + 15 = 675
Step 46: 675 + 15 = 690
Step 47: 690 + 15 = 705
Step 48: 705 + 15 = 720
Step 49: 720 + 15 = 735
Step 50: 735 + 15 = 750
Step 51: 750 + 15 = 765
Step 52: 765 + 15 = 780
Step 53: 780 + 15 = 795
Step 54: 795 + 15 = 810
Step 55: 810 + 15 = 825
Step 56: 825 + 15 = 840
Step 57: 840 + 15 = 855
Step 58: 855 + 15 = 870
Step 59: 870 + 15 = 885
Step 60: 885 + 15 = 900
Step 61: 900 + 15 = 915
Step 62: 915 + 15 = 930
Step 63: 930 + 15 = 945
Step 64: 945 + 15 = 960
Step 65: 960 + 15 = 975
Step 66: 975 + 15 = 990
Step 67: 990 + 15 = 1005
Step 68: 1005 + 15 = 1020
Step 69: 1020 + 15 = 1035
Step 70: 1035 + 15 = 1050
Step 71: 1050 + 15 = 1065
Step 72: 1065 + 15 = 1080
Step 73: 1080 + 15 = 1095
Step 74: 1095 + 15 = 1110
Step 75: 1110 + 15 = 1125
Step 76: 1125 + 15 = 1140
Step 77: 1140 + 15 = 1155
Step 78: 1155 + 15 = 1170
Step 79: 1170 + 15 = 1185
Step 80: 1185 + 15 = 1200
Step 81: 1200 + 15 = 1215
Step 82: 1215 + 15 = 1230
Step 83: 1230 + 15 = 1245
Step 84: 1245 + 15 = 1260
Step 85: 1260 + 15 = 1275
Step 86: 1275 + 15 = 1290
Step 87: 1290 + 15 = 1305
Step 88: 1305 + 15 = 1320
Step 89: 1320 + 15 = 1335
Step 90: 1335 + 15 = 1350
Step 91: 1350 + 15 = 1365
Step 92: 1365 + 15 = 1380
Step 93: 1380 + 15 = 1395
Step 94: 1395 + 15 = 1410
Step 95: 1410 + 15 = 1425
Step 96: 1425 + 15 = 1440
Step 97: 1440 + 15 = 1455
Step 98: 1455 + 15 = 1470
Step 99: 1470 + 15 = 1485
Step 100: 1485 + 15 = 1500
Step 101: 1500 + 15 = 1515
Step 102: 1515 + 15 = 1530
Step 103: 1530 + 15 = 1545
Step 104: 1545 + 15 = 1560
Step 105: 1560 + 15 = 1575
Step 106: 1575 + 15 = 1590
Step 107: 1590 + 15 = 1605
Step 108: 1605 + 15 = 1620
Step 109: 1620 + 15 = 1635
Step 110: 1635 + 15 = 1650
Step 111: 1650 + 15 = 1665
Step 112: 1665 + 15 = 1680
Step 113: 1680 + 15 = 1695
Step 114: 1695 + 15 = 1710
Step 115: 1710 + 15 = 1725
Step 116: 1725 + 15 = 1740
Step 117: 1740 + 15 = 1755
Step 118: 1755 + 15 = 1770
Step 119: 1770 + 15 = 1785
Step 120: 1785 + 15 = 1800
Step 121: 1800 + 15 = 1815
Step 122: 1815 + 15 = 1830
Step 123: 1830 + 15 = 1845
Step 124: 1845 + 15 = 1860
Step 125: 1860 + 15 = 1875
Step 126: 1875 + 15 = 1890
Step 127: 1890 + 15 = 1905
Step 128: 1905 + 15 = 1920
Step 129: 1920 + 15 = 1935
Step 130: 1935 + 15 = 1950
Step 131: 1950 + 15 = 1965
Step 132: 1965 + 15 = 1980
Step 133: 1980 + 15 = 1995
Step 134: 1995 + 15 = 2010
Step 135: 2010 + 15 = 2025
Step 136: 2025 + 15 = 2040
Step 137: 2040 + 15 = 2055
Step 138: 2055 + 15 = 2070
Step 139: 2070 + 15 = 2085
Step 140: 2085 + 15 = 2100
Step 141: 2100 + 15 = 2115
Step 142: 2115 + 15 = 2130
Step 143: 2130 + 15 = 2145
Step 144: 2145 + 15 = 2160
Step 145: 2160 + 15 = 2175
Step 146: 2175 + 15 = 2190
Step 147: 2190 + 15 = 2205
Step 148: 2205 + 15 = 2220
Step 149: 2220 + 15 = 2235
Step 150: 2235 + 15 = 2250
Step 151: 2250 + 15 = 2265
Step 152: 2265 + 15 = 2280
Step 153: 2280 + 15 = 2295
Step 154: 2295 + 15 = 2310
Step 155: 2310 + 15 = 2325
Step 156: 2325 + 15 = 2340
Step 157: 2340 + 15 = 2355
Step 158: 2355 + 15 = 2370
Step 159: 2370 + 15 = 2385
Step 160: 2385 + 15 = 2400
Step 161: 2400 + 15 = 2415
Step 162: 2415 + 15 = 2430
Step 163: 2430 + 15 = 2445
Step 164: 2445 + 15 = 2460
Step 165: 2460 + 15 = 2475

So, 15*165 = 2475